Off the map

NikoBellicGTAIV

Hi! So I was playing GTA IV and decided to take a boat and cruise into the ocean. I went pretty far away from the map, until I got bored and blew up the boat.

So, just for curiosity, what happens when you get really far away from the map? I saw a video on YouTube showing that, during multiplayer, after a while, a message appears saying you're too far away from the fun and your vehicle explodes, but I don't know if this happens in multiplayer only.